Metallurgical apparatus



y 1936- J. o. BEVTTERTON ET AL I 2,041,811

ME TALLURG I CAL APPARATUS Filed Dec. 27, 1954 3 Sheets-Sheet 1 ATTORNEY Patented May 26, I936 NlTED STATE-S orrien .PATE

MIETALIJURGICAL APPARATUS Jesse 0. Better-ton, Metuchen, and Karl A. Lindner, Rahway, N. .l., assignors to American Smelting and Refining Company, New York, N. Y., a corporation of New Jersey Application December 2'7, 1934, Serial No. 759,359

Jill Claims (Cl. 266-33) The present invention provides a metallurglcai furnace wherein the material being treated is subjected to the furnace temperaturein the presence of an atmosphere of controlled composition.

5 More particularly, the invention provides an.

improved furnace for the treatment of solderbearing metal scrap, such as scrap internal combustion engine radiators, in which furnace the solder is sweated from the scrap and collected In in a condition which enables it to be easily made 15 materially reduced by the oxidizing action of exvcess oxygen present in the heating zone of the furnace, the presence of which excess oxygen has been difiicult to avoid during the operation of the furnace. 19 A further loss of substantially directly marketable solder has been found to baincurred by the solder adhering to,- or being entrapped by the residual metal. The solder .yield has been found to be very materially increased by the provision of agitating means of suitable kind whereby the scrap may be agitated or shaken during the sweating operation, whereby the moltensolder may be dislodged from the residual scrap, and collected in suitable receptacles" beneath "the hearth of the furnace.

One of the objects of the invention, therefore,

is to provide a furnace in which the materials being treated are enabled to be subjected to an atmosphere which is maintained substantially continuously of a non-oxidizing composition.

A further object of the invention is to provide mechanism of a novel form for agitating the materials as they pass through the furnace for more effectively freeing the solder therefrom.

A still further object of the invention is to provide a furnace structure in which direct contact of the flames of the burners with the material being heated is avoided, while providing means for flooding the furnace hearth with combustion 5 gases of a non-oxidizing character and maintaining such gases in close contact with the materials on the hearth.

A still further object of the invention is to provide improved supporting mechanism for the hearth of the furnace for enabling the hearth'to be oscillated during operation, thereby more readily feeding the material being treated through the furnace.

' Further objects and advantages of the invention will become apparent as the description pro-' ceeds, the features of novelty being more definitely pointed out in the appended claims.

In the accompanying drawings which illustrate one form of the improved process,

Fig. 1 is a top view of the furnace which is shown as being partly in plan and partly in horizdntal section on the center line of the furnace, one of the furnace arches being broken away to show the construction of the hearths.

Fig. 2 is a sectional elevation of the furnace, taken along the center line thereof.

Fig. 3 is a sectional elevation taken on the line t-t of Fig. 2 looking in the direction of the arrows Fig. 4 is an elevation'of the right hand end of the furnace as viewed in Figures 1 and 2.-

. other. One of these sections, designated generally as 18 forms the furnace proper, wherein the actual melting takes place, the other section, designated generally as C, being in the nature of an extension to thefurnace, comprises the portion of the furnace where the material is subjected to a final agitation or shaping action for liberating from the residualscrap such remaining solder as may be adhering thereto.

The furnace as a whole comprises side walls l and 9, and end walls 6 i and it. These walls are formed of refractory brick, and may be provided with heat insulating layers, such as shown at it and ii, for example.

The side walls l and Q and the end walls M and. it are reinforced as appears desirable with buck-stays as indicated at it, which buck-stays are connected by tie-rods 2 i, which in turn are held in place by rods 23 extending across the top of the furnace.

Referring first to the construction of section B,

it will be seen that the furnace comprises a pair of hearths positioned in side-by-side relation, as indicatedat 25 and El, and which slope downwardly toward the right as is clearly apparent in Fig. 2. Each hearth 25, 211', comprises a plurality of hearth pans 2t, and extends'beyond the f charging end ll of the furnace for receiving the material to be treated in the furnace. Each hearth 25, ill is also mounted on the hearth beams 3|, the sections 29 being mounted on shoes 33 which are suitably secured to the beams 3|, as is showninFig.2. "f

It will be seen also from Fig. 2, that one end of each hearth pan extends into the adjacent pan, these ends being supported on shoes 35 which rest on the hearth beams 3|.

The hearth beams 3| may be I-beams which are mounted for longitudinal reciprocation. For this purpose, mechanism is provided which includes rollers 31 beneath the left-hand ends of the hearth beams 3|, these rollers being mounted on supporting standards 39.

The right-hand ends of the hearths 25 are supported on rollers 4| mounted in bearings 43 positioned on the I-beam 45, as will be clear from Figures 2 and 5. The rollers 4| are positioned at a lower elevation than the rollers 31, and engage depending brackets 41 secured to extensions 49 of each of the hearth beams 3|. The hearth pans 29 are therefore supported at a suitable inclination for the material being treated to pass along the hearths with the aid of the reciprocatory motion imparted thereto by mechanism which will now be described.

Mounted in bearings 5| secured to beams 53 of the end frame 54 is an eccentric 55, there being one of these eccentrics beneath each hearth 25, 21. The eccentric 55 operates a rod 51 which is connected with a bracket 59, extending across each hearth therebeneath. The eccentrics 55 are driven by a motor 6| coupled at 63 to a speed reducer 65, a belt 61 connecting the speed reducer 65 to the shaft 69 upon which the eccentrics 55 are mounted. The shaft 69 carries both eccentrics so that these eccentrics rotate together, but they are mounted in different phases so that at any given moment the motions of the hearths 25 and 21 are in opposite directions. The shape .of the eccentrics are such that the hearths are alternately pulled upwardly to the left as viewed in Figs. 1 and 2, and then are allowed to drop downwardly to the right, so that the material on the hearth will progressively move down the incline of the hearths responsively to the oscillatory movement of the hearths.

The oscillations of the hearths are supple-, mented by a vibratory action imparted by resilient projections or bumpers II which are mounted on the brackets 59 and engage the upright fiange of angles I3 as will be clear from Figs. 1 and 2. These bumpers II are made suitably of rubber, and the engagement thereof with the angles 13 produces a cushioning of the impact due to the dropping of the hearths, as well as the vibratory motion above referred to, which both facilitates the shaking off of the solder, and the movement of the scrap down the hearths.

It will be seen further that the furnace is provided with two arches, T5 and TI. The arch 15 is provided with a'layer of heat insulation 19, and is built of firebrick. The bottom arch I! is formed of a refractory material such as silicon carbide, through which heat from burners 8| is radiated to the hearths. -These burners 8| are disposed in the space 83 intermediate the arches.

Arch 15, together with its insulating layer 19; forms the top of the furnace. construction provides for efficient heating of the hearths, while preventing direct contact of the flames from the burners with the material on the hearths.

Beneath the hearths 25 are positioned the drip pans which receive the melted solder dripping through the holes 81 in the bottom of the hearth This double arch pan 29. The sides of the drip pans converge to the discharges 89 through which the solder runs into suitable molds, not shown, in which molds itis collected for such refining treatments as may be determined by its state of purity. I 5

Mention has been made of the fact that the burners which produce the sweating heat are separated from the hearths 25 by the arch H. However, in order to facilitate the heating of the materials on the hearths, a plurality of ports 9| 10 is provided, these ports opening from conduits 92, through which ports hot combustion gases pass from the space 83 between the arches 15 and 11 into contact with the hearths 25, and the bottom part 9| also admits hot combustion gases to the 15 drip pans for maintaining the solder therein in molten condition. On the outside of the conduits 92, ports 93 are provided, which are normally bricked up, as indicated in Fig. 5, but these bricks are left so that they may be removed readily for enabling access to be had to the ports for any desired reason.

It will be seen that the hearths 25 terminate with their lower ends above the pans which are enclosed in the section C, which section, as was mentioned above, forms an extension of the furnace B. This extension C is illustrated as being formed of brick-work, although it is obvious that it may be constructed in the same way as the furnace section B, and that B and C may be built as an integral structure instead of as distinct parts as shown.

In any event, the section 0 comprises two spaced arches, one above the other, the arch 16 being in alignment with arch l5 and arch 18 35 being in alignment with the arch 11. Arches I6 and 18 thereby form, in effect, continuations of arches I5 and 11, respectively, and the space 83 between arches 15 and I1 is continued in space 84 between arches I6 and 18.

It will be seen that the arch I8 terminates in a sloping end portion 91, which drops downwardly to a point adjacent to the pans 95, where the arch joins the end wall I3. Through the end wall l3 and sloping end 91 of the arch I8, there is placed a burner 99, positioned above and between the pans 95, which burner heats both pans.

For further facilitating the heating of the pans 95, the arch I8 is provided with a multiplicity of ports through which combustion gases from the burners 8| pass, the slope 91 of the arch l8 deflecting these gases down upon the pans 95, there being thus maintained a heavy blanket of combustion gases over the pans and between the pans and arch, thereby pre venting oxidation of the solder by air entering through the end of the furnace around the pans 95. In this connection, it will be seen that the openings I03 in the end wall l3, through which 60 the pans extend are protected against entry of air by the provision of vertically swinging doors I05 which are hinged at I01 and normally rest upon the projecting ends of the pans95, this arrangement, together with the maintenance of 65 the non-oxidizing atmosphere over the pans by -virtue of the blanket of combustion gases, e1-

between thearch l1 and hearths 25.

While, by the time the material has been discharged from the hearth pans 29 onto the pans stantial amounts of solder adhering to the re-' sidual scrap, and in order to recover such solder, mechanism is provided for agitating or shaking the pans 95 for thereby shaking off this adhering solder. For this purpose, the pans 95 are pivotally mounted adjacent to their lower ends, on trunnions H3, operating in bearings H5 mounted on anI-beam H'I extending across the end of the furnace, and mechanism is provided for imparting a shaking or vibratory motion of the pans 95.

This mechanism comprises a shaft H9, extending across the furnace and supported in bearings I M secured to I-beams I25 mounted on a supporting structure indicated generally by I25. On the shaft H9, there are mounted a plurality of cams I217, there being a pair of these cams for each pan 95, the cams being positioned substantially over the sides of the pans and the upper ends thereof. On the surface of each cam IZI-rides an arm I29, the fixed end of which is pivoted at I30 on an axis I3I, see Fig. 1, each axis being mounted in angles I33 secured to an Ji-beam I35 of the supporting structure I25. The rotation of the cams I2'I therefore causes an alternate lifting and dropping of the arms I 25, the frequency of which movement being dependent of course on the speed of rotation of the cams.

Secured to the arms I 29 are rods I37 which project through openings I55 and MI in the respective arches I5 and It. The rods I3? terminate in the loops or eyes M3 into whichare in-= serted the lugs M5 projecting from the sides of the pans 55. Supports Mil beneath the upper ends of the pans 95 providestops for limiting the downward movement of the pans. These supports Mil include an upper H-beam Mid across the interior of the furnace and a lower H-beam I5ll which projects through the furnace walls and is anchored therein.

The shaft M5 which carries the cams I27, is operated by a suitable motor M15, which is coupled to a speed reducer Bill, to which the shaft M9 is operatively connected by a chain drive i555. Operation of the motor M5 therefore drives the speed reducer I5I, the shaft M9 being operated and the arms. H25 are moved up and down responsively to movements of the cams I217, this movement being transmitted to the pans 55, through. the rods Iil'l, so that the pans correspondingly are shaken or vibrated up and down with sufficient vigor to shake off the solder adhering to the scrap. Observation doors I52 enable the operations to be suitably observed.

The bottoms of the pans 55 are provided with holes I55 through which this solder runs; and beneath the pans 95 is a drip pan I 5;? similar in every respect to the drip pans 85, the bottom sloping, as at I59 to the discharge let, this being the same construction as that of the drip pans t5.

However, discharge Iti may be at a lower level than the discharges 85 of the pans 55, so that itmay be necessary to provide a pit I55, see Fig. 3, to receive a mold I55 in which the solder is collected; and it may be necessary to support the mold on a suitable support Itl so as to po-= sition the mold for preventing the solder from splashing as it runs through the dischar e I55. For heating the drip pan I5ll, a burner may be inserted in the hood I69 provided for that purpose.

A platform "I suitably mounted on a frame I13, carries the motor- I49 and the speed reducer I5I."

For withdrawing the combustion gases from the furnace, a system of fiues is provided, which system includes the conduits I15 and Ill which open through each side wall of section into the space between the arch I8 and the shaker pans 95 as will be clear especially from Fig. 4. The conduits I15 and Ill are joined into a single flue I79 which leads to the stack, not shown, and their openings are such as to tend to withdraw any air entering the furnace through door I before such air can contact substantially with the material being treated.

The charging end of the furnace is closed by selves to those skilled in the art'; and accordingly it will be understood that it is intended and desired to embrace within the scope of this invention such modifications and changes as may be necessary to adapt it to varying conditions and uses.

What is claimed is:

l. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, a lower arch above the hearth and extending thereover for substantially the entire length thereof, an upper arch above the aforesaid arch and spaced therefrom, burners for the furnace intermediate the arches, and. a port connecting the space intermediate the arches with that between the hearth and lower arch for leading hot combustion gases from the space intermediate the arches to the hearth, the lower arch sloping downwardly for maintaining a dense blanket of combustion gases over the hearth for heating material on the hearth and for excluding air therefrom, the material on the hearth being heated both by radiation and by the hot combustion gases.

2. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, a lower arch above the hearth and extending thereover for substantially the entire length thereof, an upper arch above the lower arch and spaced therefrom, burners for the furnace intermediate the arches, a port connecting the space intermediate the arches with that between the hearth and arch thereover for leading hot combustion gases from the space intermediate the arches to the hearth, and means forming a part of the lower arch for maintaining a blanket of the said combustion gases over the hearth.

3. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the 'furnace, mechanism for enabling material to be gases to the hearth and material thereon as the material approaches the end of its travel along the hearth, and a downwardly sloping end for the arch adjacent to the hearth, the said sloping end being adjacent to the end of travel of the material along the hearth for preventing access of air to the interior of the furnace and to the hearth.

4. Metallurgical apparatus comprising the combination. with a furnace, of a plurality of movable hearths in the furnace, and common operating mechanism for the hearths, the said mechanism including means for actuating the hearths in opposite phases.

5. Metallurgical apparatus comprising the combination with a furnace, of a health for the furnace extending therethrough, spaced arches in the furnace above the hearth, av burner for the furnace intermediate the arches, and means associated with the arches for conducting combustion gases from the burner to the hearth, the said means including ports extending through the arch adjacent to the hearth, the said arch having a downwardly extending end adjacent to the material-discharge outlet of the furnace for maintaining a dense layer of the combustion gases in close engagement with the hearth and material being treated thereon.

6. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, spaced arches in the furnace above the hearth, a burner for the furnace intermediate the arches, and means associated with the arches for conducting combustion gases from the burner to the hearth, the arch adjacent to the hearth being sloped to maintain a blanket of combustion gases in close contact with the hearth and material being treated thereon.

7. Metallurgical apparatus combination with a furnace, of a hearth for the 'fuRr nace, a shaker pan associated with the hearth fo hearth, spaced arches in the furnace above the hearth, a source of combustion gases intermediate the arches, the arch adjacent to the hearth and shaker pan being provided with ports adapted to admit combustion gases to the hearth and shaker pan, the said arch being curvedniownwardly in the region of the shaker pan to deflect combustion gases-onto material on the pan and to substantially exclude admission of air to the comprising the receiving material discharged from the pan and hearth during operation of the furnace, and mechanism for shaking the pan.

8. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, a shakerpan associated with the hearth for receiving material discharged from the hearth, means for maintaining a blanket of nonoxidizing atmosphere in close engagement with the shaker pan and hearth, and exhaust means entering the furnace from each side thereof for withdrawing gases from the furnace during operation thereof.

9. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, a shaker pan associated with the hearth for receiving material discharged from ,the hearth, the arch adjacent to the hearth and shaker pan being provided with ports adapted to admit combustion gases to the hearth and shaker pan, the said arch being curved downwardly in the region of the shaker pan to deflect combustion gases onto material on the pan, and to substantially exclude admission of air to the pan and hearth during operation of the furnace, and fiues communicating laterally with the interior 'of the furnace adjacent to the said curved poring treated is adapted to move, a shaker pan as-' sociated with the hearth for directly receiving material discharged from the hearth, and drip pans beneath the hearth and shaker pan for receiving molten material from the hearth and shaker pan, the said drip pans having outlets for discharge of material collected therein and bottoms sloping to the said outlets.

11. Metallurgical apparatus comprising the combination with a furnace, of a hearth for the furnace, a shaker pan associated with the hearth for receiving material discharged from the hearth, means for maintaining a blanket of nonoxidizing atmosphere in close engagement with the shaker pan and hearth, and means for withdrawing gases from the furnace during operation thereof.

JESSE O. BETI'EBTON. KARL A. LINDNER. 

